Circuit-breaker for ignition apparatus.



A. G. KARKAU.

CIRCUIT BREAKER FOR IGNITION APPARATUS.

APPLICATION FILED JULY 23,1917.

1,294,471 a Patented Feb. 18, 1919'.

' State of UNITED STATES PA'lENT OFFICE.

ALBEET G. KARKAU, OF CLEVELAND, OHIO, ASSIGNOR TO THE K.-W. IGNITION COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

CIRCUIT-BREAKER FOR IGNITION APPARATUS.

To aZZ whom it may concern:

Be it known that I, ALBERT G. KARKAU, a citizen of the United States,-residing at Cleveland in the county of Cuyahoga and Ohio, have invented a certain new and useful Improvement in Circuit-Breakers for Ignition Apparatus, of which the following is a full, clear, and exact description.

This invention relates to improvements in circuit breakers for magnetos and-other ignition apparatus or ignition systems, and particularly to the mounting for'the roller which is carried by the breaker arm and which is engaged by the operating or controlling cam,

With circuit breakers which are opened and closed by the action of the cam on a member in the form of a roller on the breaker arm it is highly desirable in order to secure durability, that this'roller be formed out of hard metal such as hardened steel, so that it will be enabled to properly resist wear and insure long life to the breaker. How

ever, as the breaker arm is in the electric circuit of the ignition system, this arm be ing generally grounded on the framework of the apparatus, considerable difiiculty has been encountered by reason of the passage of current, between the roller and its bearing, this current causing a deterioration of the engaging surfaces of the bearing and roller, with the resultthat in a short time the roller does not operate smoothly and is r uired to be replaced.

the principal "object of the present invention is to overcome these disadvantages or diiliculties, and to provide a breaker having a roller which can be formed of metal as is desirable, and which is so mounted that current can not pass between the roller and its hearing, but the roller does, nevertheless, have a free rolling action. In other words, the roller has long life and is not subject to any material wear, nor is its bearing affectedby the action of the electric current passing through the arm carrying the roller.

The invention may be'briefiy summarized as consisting in certain novel details of construction and combinations and arrangements of parts which will be described in the specification and set forth in the appended claims.

In the accompanying sheet of drawings, Figure 1 is a face view of the circuit breaker embodying my invention; Fig. 2 is an en- Speeific ation of Letters Patent.

Patented Feb. 18, 1919.

Application filed July 23, 1917. Serial No. 182,109.

larged transverse sectional view through the roller and its mounting; and Fig. 3 is a sectional view at right angles to the sec: tion of Fig. 2. y Y

The circular breaker includes a suitable metal housing, a portion of which is shown at 10, and which may be utilized with, or

form a part of any of the well-lmown types of ignition apparatus .or systems such as a magneto. Mounted in the base of the housing there is an insulated contact member 11 carrying an adjustable contact point 12, and the breaker includes also a movable circuit breaker arm- 13 which is pivoted on a pin or screw 14, and at its free end carries a contact point 15, which coiiperates with the relatively stationary contact point 12. The breaker arm is moved toward closed position by a sprlng, here shown as a leafspring 16, secured at one end to the breaker arm and at its opposite end to a suitable part of the housing.

The circuit breaker is opened periodically by a cam 17 mounted on a central operating shaft 18, this cam having alternate flat faces and are shaped portions, the number of which depends upon the number of cylinders for which the breaker is designed. This cam n ages a roller 19 which is carried by the breaker arm, the roller being mounted between the side portions 13 (see Fig. 3) of the breaker arm, the latter being preferably formed from sheet metal withv the two side portions 13 as shown. In a breaker of this type, the breaker arm is grounded on the frame-work of the apparatus, and the current therefore passes through poses of insuring good wearing qualities,

that the roller be of metal, but with the prior constructions, for reasons previously explained, the current passing through the arm to the ground in part traverses the roller and its bearing, with the result that the bearing surfaces are aifected by the electric current. To overcome this objection I provide the present construction wherein the roller is itself insulated from the arm and its bearing, but at the same time runs very freely on anti-friction bearings.

Referring now to Figs. 2 and 3, it will be seen that the mounting for the roller includes a stationary bearing-pin 20 which extends through the side portions of the 22. Surrounding and preferably fitted tightly onto the insulating washers 21 isan annular journal 23 arranged concentric with respect to the axis of the pin 20. It will be observed that this journal 23 is insulated at all points from the pin 20, and the side portions 01. the breaker arm. Between the roller, which is in the form of an annulus, and this insulated journal, 1 provide a series of anti'iriction bearings which may be either balls or cylindrical rollers 24;, the latter being here shown.

lVith this construction, although a metal roller is employed, it is impossible for current to pass between this roller and the breaker arm or the bearing men'ibers of the roller, but nevertheless the roller can turn very freely with the result that the breaker has exceedingly long life, the roller and its mountin no longer being a point or source of t1'oubl e,- as with prior constructions.

lVhile I have shown the preferred form of my invention, and one which in practice has proven to be very ellicient and satisfactory. I do not desire to be confined to the exact details shown, but aim in my claims to cover all modifications which do not involve a (leparture from the spirit and scope or my invention.

Having described my invention, what I claim is 1. In a circuit breaker tor ignition apparatus, a pair of relatively movable contacts, an arm carrying one of the contacts, means for periodically shifting the arm, comprising a movable breake controlling member and a roller carried by the breaker arm, said roller being formed of hard Wear resisting metal and mounted to turn with reference to the arm but insulated from the latter.

2. A circuit breaker for ignition apparatus including a pivoted breaker arm, means for periodically shifting the same comprising a cam and a metal roller carried by the arm and engaged by the cam, and an insulated bearing for the roller.

3. In a circuit breaker for ignition apparatus, a pivoted breaker arm, means for periodically shifting the same, comprising a rotary cam and a roller carried by the arm, an annular bearing member for the roller, anti-friction bearing members between said hearing member and the roller, said bearlng member and roller being insulated from the arm.

4. A circuit breaker for ignition appara tus including a pivoted breaker arm, means for periooically shifting the same comprising a rotary cam, a roller carried by the arm and adapted to be engaged by the cam, a pin about which the roller is adapted to turn and 1 mounted in the arm, an annular journal carried by the pin and insulated from the latter and from the arm, and anti-friction bearing members between said journal and the. roller.

5. A circuit breaker for ignition apparatus including a pivoted breaker arm, means for periodically shifting the armcomprising a rotary cam and a roller carried by the arm and formed of hard wear resisting metal, and a mounting for the roller comprising a. journal about which the roller turns, sa'd journal being insulated from the arm.

In testimony Whereoi I hereunto aliir: my signature.

G. KARKAU.

TIE- 

